Fluid flow transfer device

ABSTRACT

Materials are transported through a conduit by the action of an impelling fluid introduced at a low mass flow rate and high velocity into the conduit. The impelling fluid enters the conduit along the inside wall surface with a velocity vector parallel to the flow path of the conduit for smooth transfer of energy to a compatible carrier fluid under laminar flow conditions.

United States Patent Baker [1 1 3,655,298 [451 Apr. 11, 1972 [54] FLUID FLOW TRANSFER DEVICE [72] Inventor: Hayward Baker, PO. Box 887, Menlo Park, Calif. 94025 2,297,681 10/1942 Anderson et al..... ..417/ 197 X 3,448,691 6/1969 Frazier ..4l7/l97 X 3,447,467 6/ 1969 Heinge ..4l7/ 197 X Primary Examiner-Carlton R. Croyle Assistant Examiner-Richard F. Gluck Attorney-Clarence A. OBrien and Harvey B. Jacobson [57] ABSTRACT Materials are transported through a conduit by the action of an impelling fluid introduced at a low mass flow rate and high velocity into the conduit. The impelling fluid enters the conduit along the inside wall surface with a velocity vector parallel to the flow path of the conduit for smooth transfer of energy to a compatible carrier fluid under laminar flow conditions.

7 Claims, 3 Drawing Figures PATENTEDAFR 11 m2 3, 655,298

Hay ward Baker [NV LNTOR.

FLUID FLOW TRANSFER DEVICE This invention relates to the transportation of materials by means of a fluent medium flowing through a conduit, flow being induced by injection of an impelling fluid into the conduit.

Conveyance of materials in solid, liquid or gaseous states by a fluent medium through a conduit utilizing an impelling fluid to induce flow, is well known. Generally, the impelling fluid enters the conduit an an angle to the direction of flow of the carrier or transporting medium. Such fluent conveying devices are relatively inefficient because of the turbulence produced by entry of the impelling fluid at an angle to the general direction of flow. Aside from the resulting inefficiency, the turbulence produces abrasion of the conduit surfaces particularly where an abrasive material such as particulate solids are being transported.

It is therefore an important object of the present invention to provide a conveying device of the aforementioned type which avoids the turbulence phenomena heretofore associated with such devices. Accordingly, more efficient use of the energy of the impelling fluid is achieved and surface abrasion avoided so as to reduce rapid wear.

In accordance with the present invention, a nozzle assembly is provided between adjacent sections of a flow conduit through which an impelling fluid is introduced into the conduit for inducing flow therethrough. The nozzle assembly is arranged however so that the impelling fluid enters the flow passage of the conduit on the inside of the conduit wall in a direction substantially parallel to the flow of the fluent medium therethrough. Thus, a laminar flow condition is maintained within the body of the flowing medium as it passes through the nozzle assembly. This is accomplished by passage of the impelling fluid through a flow chamber having a critical dimensional and geometrical relationship to the conduit, the flow conditions and restricted passage through which the impelling fluid is delivered from its supply chamber.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIG. 1 is a side sectional view through a flow inducing nozzle assembly and adjacent conduit sections constituting one embodiment of the present invention.

FIG. 2 is an enlarged transverse sectional view taken substantially through a plane indicated by section line 2-2 in FIG. 1.

FIG. 3 is an enlarged partial sectional view of a portion of the nozzle assembly.

Referring now to the drawings in detail, the flow inducing nozzle assembly generally denoted by reference numeral is shown associated with adjacent conduit sections 12 and 14 to which the nozzle assembly is connected. By means of the nozzle assembly, flow of a carrier medium is induced from an upstream location through conduit section 12 toward a downstream location through conduit section 14. The carrier medium may be in the form of a compressible or noncompressible fluid, liquid or gas or admixtures thereof in a flowing condition for transport of difierent materials such as particulate solids or entrained liquids and gases. The carrier medium must however be compatible with a pressurized impelling fluid supplied to the nozzle assembly by a conduit 16 from a suitable source (not shown). For example, when a compressible carrier medium such as air is utilized, the impelling fluid should also be a compressible gas inert with respect to the air. On the other hand, when a noncompressible carrier medium such as water is utilized, the impelling fluid should be a noncompressible fluid including water.

The nozzle assembly in the illustrated embodiment, includes a generally cylindrical nozzle section 18 connected by any suitable means to the upstream conduit section 12 and a second nozzle section 20 connected to the downstream conduit section 14. The nozzle sections 18 and 20 are interconnected in axially adjusted spaced relationship to each other by means of threaded portions 22 and 24 with a suitable seal 26 therebetween to prevent leakage. As shown, both nozzle sections 18 and 20 are provided with internal cylindrical wall surfaces 28 and 30 which are coaxially aligned with the conduit sections 12 and 14 and are of equal diameter. Accordingly, a constant flow area passage extends through the nozzle assembly 10 between the conduit sections interconnected thereby.

An annular receiving chamber 32 is formed between the portions 22 and 24 of the nozzle sections in communication with the supply conduit 16. Accordingly, the receiving chamber 32 will be filled with an impelling fluid under a predetermined pressure. In one successful installation of the invention, air was used as the impelling fluid under a pressure of p.s.i.a.

The downstream end of the nozzle section 18 is provided with a conical wall surface 34 as more clearly seen in FIG. 3 which is closely spaced from a parallel surface 36 on the nozzle section 20 to form an annular slit or restricted passage 38 between the noule sections in communication with the receiving chamber 32. The narrow passage 38 in one successful embodiment of the invention was inclined at an angle of 60 to the longitudinal axis of the conduit passage. The passage 38 thus conducts impelling fluid from the chamber 32 into a passage chamber or groove 40 abruptly enlarging the flow area of passage 38 between the conical wall surface 34 on nozzle section 18 and the parallel wall surface 42 forming one side of the chamber 40 perpendicular to the end wall surface 44. Thus, flow of the impelling fluid from the chamber 32 passes from the narrow passage 38 through the wider chamber passage 40 into the conduit flow passage. The flow chamber 40 as observed from FIGS. 1 and 3, is in peripheral communication with the conduit flow passage and extends at an angle thereto parallel to the angle of the passage 38.

In one embodiment of the invention having an angle of 60 between the flow passage 38 and the longitudinal axis of the conduit passage, the width (B) of the chamber 40 as illustrated in FIG. 3 was 0.031 inch whereas the width (A) of the restricted passage 38 was adjusted between 0.004 inch and 0.008 inch. The diameter (D) of the conduit passage was 2 inches. In view of such relative dimensions, a relatively low mass flow rate of impelling fluid was introduced into the conduit passage. However, in view of the relatively narrow width (A) of the flow passage 38, the impelling fluid enters the conduit passage at a relatively high flow velocity as compared to the carrier medium.

From a consideration of well known fluid dynamic theory and principle, the momentum of the impelling fluid at high velocity entering the chamber 40, reduces the static pressure therein below that of the carrier medium within the conduit flow passage. A differential static pressure thereby causes a vertical change in the flow path 46 of the impelling fluid as it passes from the passage 38 through the chamber 40. The curvature of the flow path 46 in relation to the angle of the passage 38 to the longitudinal axis of the conduit flow passage, is such that the impelling fluid when entering the flow passage will have a velocity vector substantially parallel to the longitudinal axis of the conduit flow passage or perpendicular to its flow area as illustrated in FIG. 3. Thus, the kinetic energy of the impelling fluid layer on the conduit wall surface 30 is smoothly transferred to the adjacent layers of the carrier medium for a concave velocity distribution profile in a downstream direction (i.e. a velocity decreasing from the wall surfaces toward the center of the cross-sectional flow area within the nozzle assembly. This velocity distribution profile will of course become convex at some location downstream of the nozzle assembly because of flow medium viscosity and conduit wall friction.

In accordance with the operational theory aforementioned, it should be apparent that the impelling fluid undergoes a directional change as it passes through the chamber 40 so that when the chamber 40 is properly dimensioned in relation to the angle of the passage 38, its restricted flow area, the pressure of the impelling fluid, the dimension of the conduit flow passage and the characteristics of the carrier medium conducted therethrough, the desired results will be obtained whereby the impelling fluid changes direction and thus enters the conduit flow passage parallel to the direction of flow so as to avoid turbulence and produce a smooth transfer of energy. For the conditions and dimensions hereinbefore specified, the operative ratio of the width of flow chamber 40 to the width of passage 38 was empirically found to be between 4:1 and 8:1 in order to achieve the desired results.

The referred to advantageous results attributable to the described invention have been verified by various tests including the coating of the conduit flow passage surfaces 28 and 30 with a thin film of oil so as to observe the action of the impelling fluid which carried the oil along the wall surface 30 without any indication of turbulence or disturbance of laminar flow conditions. Further, a marked reduction in surface abrasion and wear has been experienced with fluid impelling nozzles constructed and operated in accordance with the present invention as compared to prior art arrangements in which impeiling fluid is injected into the conduit flow passage at an angle to the conduit flow direction or longitudinal axis of the conduit.

In construction the nozzle assembly the spacing between the nozzle sections 18 and 20 was made adjustable in order to vary the width (A) of the passage 38 in order to determine the operative ratio range aforementioned. Where the width (A) of the passage 38 is too wide, the increased mass flow rate of impelling fluid relative to the carrier fluid reduced the influence of the pressure diiferential on the path of the impelling fluid so that the impelling fluid entered the flow conduit at an angle causing turbulence as in the case of prior art arrangements. When the width (A) of the passage 38 was made too small, the mass flow rate of the impelling fluid was out of proportion to the relatively large mass flow rate of the carrier fluid and therefore ineffective to cause any substantial movement thereof.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

I claim:

1. ln combination with a conduit through which a flow medium is conducted along a path perpendicular to a constant flow area, means for impelling said medium through the conduit at a relatively high mass flow rate comprising chamber means in peripheral fluid communication with said conduit at a lower static pressure during flow of said medium through the conduit, supply means from which an impelling fluid is introduced into the conduit at a relatively low mass flow rate, restricted passage means conducting the impelling fluid from the supply means to the chamber means at a high flow velocity relative to the flow velocity of the medium within the conduit for establishing said lower static pressure within the chamber means to produce a vortical change in flow direction of the impelling fluid passing through the chamber means, said passage means conducting the impelling fluid at an angle to said path of the medium whereby the impelling fluid enters the conduit from the chamber means substantially perpendicular to the flow area of the conduit, said chamber means including a nozzle section having an internal wall surface equal in diameter to that of the conduit, and an annular groove formed in the internal wall surface projecting radially outward parallel to said angle of the passage means, said annular groove including a side wall parallel to and spaced downstream from the passage means, said passage means including a second nozzle section having a conical wall portion spaced from the first mentioned nozzle section to form a restricted flow area for the impelling fluid that is abruptly enlarged within the chamber 4 I n 2. The combination of claim 1 wherein said supply means includes a fluid receiving chamber formed between said two nozzle sections in fluid communication with the passage means and radially spaced from the flow area of the conduit.

3. The combination of claim 2 wherein the flow area ratio of the chamber means to the passage means is approximately between 8:l and 4:1.

4. In combination with a conduit through which a flow medium is conducted under a relatively high static pressure along a path perpendicular to a constant flow area, means for impelling said medium through the conduit at a relatively high mass flow rate comprising chamber means in peripheral fluid communication with said conduit, suppiy means from which an impelling fluid is introduced into the conduit under a relatively low static pressure and at a relatively low mass flow rate, restricted passage means connected to the supply means upstream of and restricted in flow area relative to the chamber means for injecting the impelling fluid into the conduit through the chamber means at a high flow velocity relative to the flow velocity of the medium within the conduit establishing said relatively low static pressure within the chamber means thereby to produce a vortical change in flow direction of the impelling fluid passing through the chamber means, said restricted passage means conducting the impelling fluid at an angle to said path of the medium whereby the impelling fluid enters the conduit from the chamber means in a direction substantially perpendicular to the flow area of the conduit, the flow area ratio of the chamber means to the passage means being approximately between 8:1 and 4:1.

5. In combination with a conduit through which a flow medium is conducted along a predetermined path, means for impelling said medium through the conduit at a relatively high mass flow rate comprising a source of impelling fluid under pressure, restricted passage means for conducting said impelling fluid from the source radially inwardly toward the conduit at an angle to said path, and flow direction regulating means connected to the passage means radially outwardly of the conduit and responsive to a static pressure differential for introducing the impelling fluid into the conduit parallel to the path of the medium.

6. The combination of claim 5 wherein said flow direction regulating means includes a downstream enlargement of the flow area of the passage means accommodating a vertical change in the flow path of the impelling fluid under said static pressure differential.

7. The combination of claim 6 wherein said flow area enlargement is between approximately four and eight times the flow area of the passage means. 

1. In combination with a conduit through which A flow medium is conducted along a path perpendicular to a constant flow area, means for impelling said medium through the conduit at a relatively high mass flow rate comprising chamber means in peripheral fluid communication with said conduit at a lower static pressure during flow of said medium through the conduit, supply means from which an impelling fluid is introduced into the conduit at a relatively low mass flow rate, restricted passage means conducting the impelling fluid from the supply means to the chamber means at a high flow velocity relative to the flow velocity of the medium within the conduit for establishing said lower static pressure within the chamber means to produce a vortical change in flow direction of the impelling fluid passing through the chamber means, said passage means conducting the impelling fluid at an angle to said path of the medium whereby the impelling fluid enters the conduit from the chamber means substantially perpendicular to the flow area of the conduit, said chamber means including a nozzle section having an internal wall surface equal in diameter to that of the conduit, and an annular groove formed in the internal wall surface projecting radially outward parallel to said angle of the passage means, said annular groove including a side wall parallel to and spaced downstream from the passage means, said passage means including a second nozzle section having a conical wall portion spaced from the first mentioned nozzle section to form a restricted flow area for the impelling fluid that is abruptly enlarged within the chamber means.
 2. The combination of claim 1 wherein said supply means includes a fluid receiving chamber formed between said two nozzle sections in fluid communication with the passage means and radially spaced from the flow area of the conduit.
 3. The combination of claim 2 wherein the flow area ratio of the chamber means to the passage means is approximately between 8:1 and 4:1.
 4. In combination with a conduit through which a flow medium is conducted under a relatively high static pressure along a path perpendicular to a constant flow area, means for impelling said medium through the conduit at a relatively high mass flow rate comprising chamber means in peripheral fluid communication with said conduit, supply means from which an impelling fluid is introduced into the conduit under a relatively low static pressure and at a relatively low mass flow rate, restricted passage means connected to the supply means upstream of and restricted in flow area relative to the chamber means for injecting the impelling fluid into the conduit through the chamber means at a high flow velocity relative to the flow velocity of the medium within the conduit establishing said relatively low static pressure within the chamber means thereby to produce a vortical change in flow direction of the impelling fluid passing through the chamber means, said restricted passage means conducting the impelling fluid at an angle to said path of the medium whereby the impelling fluid enters the conduit from the chamber means in a direction substantially perpendicular to the flow area of the conduit, the flow area ratio of the chamber means to the passage means being approximately between 8:1 and 4:
 5. In combination with a conduit through which a flow medium is conducted along a predetermined path, means for impelling said medium through the conduit at a relatively high mass flow rate comprising a source of impelling fluid under pressure, restricted passage means for conducting said impelling fluid from the source radially inwardly toward the conduit at an angle to said path, and flow direction regulating means connected to the passage means radially outwardly of the conduit and responsive to a static pressure differential for introducing the impelling fluid into the conduit parallel to the path of the medium.
 6. The combination of claim 5 wherein said flow direction regulating means includes a downstream enlargement of the flow area of the passage means accommodating a vortical change in the flow path of the impelling fluid under said static pressure differential.
 7. The combination of claim 6 wherein said flow area enlargement is between approximately four and eight times the flow area of the passage means. 